mqttdevicemanager/assethandler.py
2026-03-15 13:28:38 +10:30

118 lines
3.4 KiB
Python
Executable File

#! /usr/bin/env python3
import asyncio
import uuid
import aioserial
import aiomqtt
import pyubx2
BAUD = 115200
class SerialMQTTHandler:
def __init__(
self,
handler_id: str,
serial_port: str,
mqtt_host: str = "127.0.0.1",
mqtt_port: int = 1883,
):
self.handler_id = handler_id
self.serial_port = serial_port
self.mqtt_host = mqtt_host
self.mqtt_port = mqtt_port
# Serial
self.ser = aioserial.AioSerial(
port=serial_port,
baudrate=BAUD,
timeout=0.05, # 50 ms
)
# MQTT client
self.client_id = f"{handler_id}-{uuid.uuid4()}"
self.mqtt_client = aiomqtt.Client(
mqtt_host, port=mqtt_port, identifier=self.client_id
)
# Topic base
self.topic_base = f"asset/{handler_id}"
async def parse_serial(self):
buffer = bytearray()
class StreamWrapper:
def read(inner_self, n=1):
if not buffer:
raise BlockingIOError
out = buffer[:n]
del buffer[:n]
return bytes(out)
ubr = pyubx2.UBXReader(StreamWrapper(), parsing=True)
while True:
chunk = await self.ser.read_async(200)
if chunk:
buffer.extend(chunk)
try:
while True:
raw, parsed = ubr.read()
if raw is None:
break
yield raw, parsed
except (pyubx2.UBXStreamError, BlockingIOError, Exception):
pass
else:
await asyncio.sleep(0)
async def serial_reader_task(self):
async for raw, parsed in self.parse_serial():
if isinstance(parsed, pyubx2.UBXMessage):
for name, value in vars(parsed).items():
if name.startswith("_"):
continue
topic = f"{self.topic_base}/{parsed.identity}/{name}"
await self.mqtt_client.publish(topic, value, qos=1, retain=True)
else:
print(parsed)
await self.mqtt_client.publish(f"{self.topic_base}/raw", raw)
await self.mqtt_client.publish(f"{self.topic_base}/parsed", str(parsed))
async def mqtt_command_writer_task(self):
command_topic = f"{self.topic_base}/command"
async for message in self.mqtt_client.messages:
topic = str(message.topic)
if topic == command_topic:
await self.ser.write_async(message.payload)
async def run(self):
command_topic = f"{self.topic_base}/command"
interval = 5
while True:
try:
async with self.mqtt_client as client:
await client.subscribe(command_topic)
await asyncio.gather(
self.serial_reader_task(),
self.mqtt_command_writer_task(),
)
except aiomqtt.MqttError as e:
print(
f"[{self.handler_id}] MQTT connection error: {e}. Reconnecting in {interval}s..."
)
await asyncio.sleep(interval)
if __name__ == "__main__":
async def main():
handler = SerialMQTTHandler("example-gps", "/tmp/ttyV0")
await handler.run()
asyncio.run(main())